Hume's Scepticism with Regard to Reason: A Reconsideration

Hume Studies Volume XXII, Number 2, November 1996, pp. 211-229 Hume's Scepticism with Regard to Reason: A Reconsideration FRANCIS W. DAUER The significance of Book I, Part iv, Section 1 of the Treatise may well be the naturalistic conclusion Hume draws from his skeptical argument.1 Still, the conclusion is based on the argument, and the tide of opinion seems to be against the argument despite William Morris's valiant attempt to defend it.2 Hume's argument certainly seems fishy and the conclusion that reliance on reason would lead to the total suspense of judgment is clearly unappealing. Unfortunately, I can't share the critics' confidence that Hume's argument is mistaken. I think a reasonably systematic attempt to understand Hume's argument will show that the critics haven't clearly won the day. Hume's skeptical argument makes two points: (a) all knowledge degenerates to probability, and (b) if we follow the dictates of reason, all probabilities reduce to nothing. Without too much injustice, I think we can take (a) to claim that all a priori beliefs are attended with some doubt, and take (b) to claim that if we rely on reason, we can have no confidence in a belief that is attended with doubt. I shall mainly be concerned with (b), but perhaps a few words about (a) are in order. Concerning (a), Hume's central argument seems to be this: Now as none will maintain, that our assurance in a long numeration exceeds probability, I may safely affirm, that there scarce is any Francis W. Dauer is at the Department of Philosophy, University of California, Santa Barbara, Santa Barbara CA 93106-3090 USA. 212 Francis Dauer proposition concerning numbers, of which we can have a fuller security. For 'tis easily possible...to reduce the longest series of addition to the most simple question.... But knowledge and probability...must be either entirely present, or entirely absent.... if any single addition were certain, every one woul'd be so, and consequently the whole or total sum. (T 181) In fact, any complex sum can be reduced to a series of simple +1 and -1 operations: 55,438+12,134 = [55,438+l]+[12,134 -1] = 55,439+12,13 = ... 67,572+0 = 67,572. Hume's point is: Because the complex sum can be mistaken only if some of the simple steps are, we shouldn't have doubts about the complex sum if there were no doubts about the simple steps. Given our doubts about the complex sum (because of past mistakes in similar cases), the a priori beliefs corresponding to the simple steps are also dubitable (because we must have been mistaken in similar cases in the past). The obvious response is along the following line: "In my mind I recognize well enough what adding 1 or subtracting 1 is; but in writing this down in a calculation, I mistranscribe my belief. Thus, while I may write '55,437' for '55,438+1', in my mind I clearly saw that 55,438+1 = 55,439." Much in the same region of thought is Imlay's suggestion: Hume himself...has...insisted on the inconstancy of our mental powers. But, surely, such inconstancy would allow me to add 7 and ^ «¡au apt 1 9 fnrapt smH ruit Ηπτατπ 1 3 ïnctpaH ^ puwcib. oui, bureiy, such incoiisiancy wuuiu 5, say, get 12, forget and put down 13 instead Granting that slips of the pen or memory can happen, it's dubious that our errors are always of this sort. First, it's far from clear that there is always a separate act of the mind that recognizes the correct sum so that the error is only a faulty transcription or recollection. Isn't it more likely that in most cases I do the addition in the writing? But then, even simple additions are fallible. Secondly, even if there is a separate act of the mind, surely I believe that what I wrote down is correct—for example, that '55,438+1 = 55,437' is true. If we allow disquotation, I did mistakenly believe that 55,438+1 = 55,437. Though disquotation requires care, given that I perceive the...